362results about "Headers" patented technology

The invention relates to a multi-modal fusion corn harvester header height adaptive adjustment method and system, and belongs to the technical field of automation control, the method comprises the following steps: using a binocular camera to collect crop images, and preprocessing the crop images to obtain a depth map; the image is input into a YOLOV8n model, and coordinates of a center point at the bottom of a bounding box of the corncob are obtained through model operation; performing plane fitting on the depth map to obtain a ground height; calculating a corn ear height initial value based on the ground height and the center point coordinate; vibration data of working of the harvester is collected to perform vibration compensation on the initial height value to obtain a height correction value; and dynamically adjusting the header height of the harvester by adopting a dynamic fuzzy PID algorithm based on the correction value. According to the method, the target detection model and the dynamic fuzzy PID algorithm are combined, so that the problems of low visual detection precision and control response lag of existing agricultural machinery in a complex field scene are solved, and crop loss in harvesting operation is effectively reduced.

The invention discloses a harvester header height control method and system based on multi-source sensing information fusion, and belongs to the field of agricultural machinery automation control. The problems that in the prior art, actually-measured height detection deviation is large, and the height detection data source is single are solved, the longitudinal height and the transverse inclination angle of the header are calculated and adjusted in real time through multi-source sensor data, the accuracy of the height and the posture of the header is guaranteed from multiple dimensions so as to adapt to the complex working environment, and the working efficiency is improved. The precise control process of a hydraulic loop driving system on longitudinal and transverse hydraulic cylinders is defined, a reasonable height difference threshold value and a reasonable angle difference threshold value are set, fine regulation and control of the height of the header are achieved, abnormal conditions such as crop cutting missing and soil shoveling are reduced, crop and topographic feature points are extracted through a visual detection system and a deep convolutional neural network, and the accuracy of crop cutting is improved. A terrain curve and an operation plane can be accurately constructed, accurate operation path guidance is provided for a header, the accuracy and quality of harvesting operation are effectively improved, and the loss rate is reduced.

A hybrid flute for a stalk roll may be configured with a sharp edge positioned between a first blunt edge and a second blunt edge along a length of the flute edge. The flute edge may extend radially outward from a main cylinder of the stalk roll. The flute edge may be engaged with a radius at the base of the flute edge, and a flute base may extend from the radius. A plurality of flute bases positioned adjacent to one another may be configured to form a main cylinder for the stalk roll. Wherein the main cylinder and one or more support members are formed of separable halves, the support members comprising inside planar surfaces for attachment to a square drive shaft.

The utility model relates to a corn harvesting device, and in particular to an ear and stalk harvesting platform, comprising a straw-pulling assembly, a stem-pulling roller located below the straw-pulling assembly, a bottom auger located below the stem-pulling roller, a throwing device located at the output end of the bottom auger, and an ear auger for transporting ears; it also comprises a front cross-knife assembly and a roller assembly located between the stem-pulling roller and the bottom auger. The ear and stalk harvesting platform of the utility model, by providing a conical head and spiral ribs and two types of stem-pulling plates on the stem-pulling roller to form a roller-plate combined stem-pulling, achieves smooth stem pulling without clogging, without damaging the stalks and ears, and has high stem pulling efficiency; by providing a roller assembly, the corn stalks are fully chopped, the structure is simple, and the working efficiency is high; the chopped stalks can be quickly, evenly and smoothly passed through the bottom auger through the oval-shaped structure-designed feed port into the fan and then thrown out, avoiding the stalks squeezing and blocking the channel.

The embodiment of the invention provides a header component adjustable automatic control method and device, electronic equipment and harvesting machinery, and relates to the technical field of agricultural machinery. The header part adjustable automatic control method comprises the steps that it is determined that an automatic control mode is in an activated state, and the working state of a header is determined according to the running driving mechanism state and the main clutch state of a machine where the header is located and the opening degree state of a handle for controlling the advancing direction; when the working state is a harvesting state, working parameters of an execution variable pump corresponding to all parts of the header are determined according to the harvesting speed and the harvesting working condition; and correcting the working parameters of the execution variable pump based on the detection signal of the header monitoring point position monitored in the harvesting state. According to the embodiment, the rotating speed and the rotating direction of the header part can be automatically adjusted, the working efficiency of the harvesting process is improved, meanwhile, abnormal blockage of the header can be automatically monitored and processed, and the operation quality is improved.

The invention provides a fresh corn header, which belongs to the technical field of corn harvesting and comprises a plurality of groups of harvesting chain wheels, each group of harvesting chain wheels are connected through a harvesting chain, the outer side of each harvesting chain is connected with a plurality of pushing blocks, and a material channel is formed between every two adjacent harvesting chains; the bottom of the harvesting chain wheel on one side is fixed to a bottom plate, and the bottom plate is fixed to the table body. An elastic ear picking device is further arranged on the bottom plate and arranged on the inner side of the harvesting chain, and a harvesting chain wheel on the other side of the elastic ear picking device is fixed to the table body. The table body is also connected with a stalk pulling assembly for pulling corn stalks; the stem pulling assembly is located at the bottom of the elastic ear picking device. According to the corn harvester, the elastic ear picking device moves along with corn when the stalk pulling assembly separates corn stalks from the corn, stress of corn kernels is reduced, meanwhile, the elastic ear picking device can change the size of a material channel according to the size of the corn, rolling of the corn is reduced, and therefore damage to the corn is reduced.

A regenerated rice harvesting platform and a regenerated rice combine harvester, belonging to the technical field of regenerated rice combine harvesters. The utility model includes a harvesting platform frame, a reed wheel arranged above the front of the harvesting platform frame, a reciprocating cutter arranged at the entrance of the harvesting platform frame, a harvesting platform spiral auger arranged at the rear of the harvesting platform frame, a left grain divider and a right grain divider arranged on both sides of the entrance of the harvesting platform frame, a reed wheel supporting oil cylinder arranged on both sides of the harvesting platform frame, and a transmission mechanism arranged on one side of the harvesting platform frame. The working width of the harvesting platform between the left grain divider and the right grain divider is less than or equal to 2.5 meters. The regenerated rice harvesting platform is used in conjunction with a crawler-type walking chassis, and the crawler-type walking chassis includes a left crawler and a right crawler, and the width of each crawler is less than or equal to 280 mm. The utility model can effectively meet the use needs of small plots in hilly and mountainous areas, taking into account the requirements of passability and rolling rate.

The utility model discloses a corn header ear picking frame with a flail knife structure, which comprises a gear box arranged on a corn harvester, and further comprises a header mechanism for harvesting corn, an ear picking mechanism for guiding corn ear picking and a flail knife mechanism for smashing corn stalks and returning the corn stalks to the field, the header mechanism is assembled on one side of the gearbox, the ear picking mechanism is arranged on the lower portion of the end, away from the gearbox, of the header mechanism, and the flail knife mechanism is arranged on one side of the lower portion of the header mechanism corresponding to the ear picking mechanism. The corn harvester is simple and convenient to adjust, easy to overhaul, small in number of transmission structures, small in occupied space and small in power loss, the ear picking mechanism is matched with the flail knife mechanism, cut stalks can be smashed and returned to the field in the harvesting operation process, multiple functions are achieved through one-time operation, and the operation efficiency is improved.

The invention provides a harvester header self-adaptive regulation and control method, relates to the technical field of agricultural machinery intellectualization, and aims to solve the problem that a header and a reel are difficult to quickly adjust in the prior art. Self-adaptive regulation and control of the header and the reel are achieved, the height of the header and the rotating speed of the reel can be accurately adjusted according to actual operation conditions such as ground fluctuation and crop density, the regulation and control accuracy and adaptability are improved, factors such as the height of the two sides of the header and the ground, the operation speed and the crop density are comprehensively considered, and the regulation and control accuracy is improved. The height of the header and the rotating speed of the reel are adjusted more accurately, so that harvesting operation is smoother, and the problems of header damage, crop omission and the like are solved.

The invention discloses a multifunctional silage maize harvester control system, and relates to the technical field of silage maize harvesters, the multifunctional silage maize harvester control system comprises a data acquisition module, the data acquisition module is used for acquiring parameter data of crops, specifically including planting density and row spacing data of the crops and height data of the crops; the control module is used for adjusting all equipment parameters of the silage maize harvester, specifically, according to crop parameter data collected by the data collection unit, adjusting signals for a header of the silage maize harvester are output, and the specific adjusting signals comprise the height and position of the header and the line spacing and cutting speed of the header; the silage maize harvester is adjusted according to the adjusting signal; through the control module, the function of automatically adjusting the height, the position, the line spacing and the cutting speed of the header of the silage maize harvester is achieved, the problem that frequent manual adjustment is needed can be solved, the frequency of manual adjustment is reduced, the working efficiency is improved, meanwhile, the adaptability to crops with different planting densities is improved, and the grain waste phenomenon is reduced.

A header assembly (200) for an agricultural vehicle, the header assembly comprising: a header (201) comprising a lower surface (203); and at least one gauge wheel assembly comprising: a gauge wheel (222); and a coupling mechanism (226) coupling the gauge wheel (222) to the header (201), the coupling mechanism (226) including: a hydraulic cylinder (230) configured to selectively extend from a retracted configuration towards an extended configuration to urge a lower edge of the gauge wheel (222) below and away from the lower surface (203) of the header (201); and a biasing element (228) arranged to bias the hydraulic cylinder (230) to the retracted configuration.

The invention relates to the technical field of agricultural machinery, and discloses a corn non-row-control harvester header intelligent lifting device which comprises a header body and a vehicle body, a fixing block is fixedly connected between the header body and the vehicle body, and the bottom side of the fixing block is fixedly connected with a second connecting block. A first connecting block is fixedly connected to the end, away from the fixing block, of the second connecting block, a first rotating shaft is fixedly connected to the bottom of the header body, an angle adjusting assembly and an anti-winding assembly are arranged between the header body and the second connecting block, and a lubricating assembly is arranged at the top of the vehicle body. A first motor is fixedly connected to the outer wall of the vehicle body. Through cooperation of a laser radar, an ultrasonic sensor, a controller, a first motor, a gear, a rack, a fixing block and other structures, accurate height adjustment and stable lifting of the header are achieved, and improvement of corn harvesting quality and operation efficiency is facilitated.

The invention discloses a harvester header height pre-judgment type adjusting system and method and a harvester, and relates to the technical field of harvester header height adjusting.In the system, a look-ahead sensing module is used for detecting terrain data in real time and generating a terrain profile map according to the terrain data in front of the harvester; the multi-parameter acquisition module is used for acquiring the vehicle speed of the harvester and the crop density and crop humidity data in front of the harvester in real time; the central control module is used for receiving and performing multi-parameter fusion and pre-judgment control on the terrain profile map, the vehicle speed, the crop density and the crop humidity data to generate a hydraulic control instruction; the hydraulic execution module is used for receiving the hydraulic control instruction and adjusting the header height of the harvester according to the hydraulic control instruction. According to the method, the problems of sensing range limitation and hydraulic delay are solved through terrain change pre-judgment and multi-parameter fusion control, and the harvesting quality and the operation efficiency under the complex working condition are improved.

The utility model discloses an automatic header profiling device which comprises a header assembly and a detection body arranged on the header assembly. The detection main body comprises a detection shell, a profiling structure which is hinged to the lower end part of the detection shell, is used for being attached to the ground and swings relative to the detection shell along with the change of the ground, and a flexible structure which is connected with the free end of the profiling structure and the detection shell and is used for fixing the maximum distance between the free end of the profiling structure and the detection shell; the profiling sensor is arranged in the detection shell, and the knuckle bearing assembly is connected with the end, close to the detection shell, of the profiling structure and the profiling sensor and used for transmitting the angle variation of the profiling structure swinging relative to the detection shell to the profiling sensor. The profiling sensor does not bear the acting force applied by the profiling structure any more, and the service life of the profiling sensor is long. In addition, the utility model further discloses a silage maize harvester comprising the header automatic profiling device.

The utility model relates to an adjustable split type comb plate silage harvester header, and belongs to the technical field of silage harvesting equipment. According to the technical scheme, a grain dividing fork (5) is arranged at the front end of a front feeding roller (2), cutting boards of the front feeding roller (2) and a rear feeding roller (3) are arranged in a crossed and staggered mode, and a split type comb plate (6) is arranged between the front feeding roller and the rear feeding roller; the split type comb plate comprises a front comb plate and a rear comb plate which are detachably connected, the fit clearance between the front comb plate and the rear comb plate can be adjusted, and the working distance between the front comb plate and the rear feeding roller can be changed by adjusting the fit clearance between the front comb plate and the rear comb plate. Therefore, the conveying requirement for cutting of different types of materials is met. According to the utility model, the split comb plate is adopted, so that material blockage during working of the header is reduced, the comb plate is convenient to replace and maintain, and the working efficiency during harvesting is improved; the feeding device has the characteristics of high feeding efficiency, uniform feeding, efficient and stable conveying and the like.

The utility model relates to a cutting device of a corn harvesting header, and belongs to the technical field of agricultural harvesters. According to the technical scheme, the stem pulling device comprises a left stem pulling roller assembly and a right stem pulling roller assembly which are axially symmetrically arranged on a rack body, each stem pulling roller assembly comprises a stem pulling roller main shaft, a stem pulling plate, cutters and a spiral conveying shaft, the rear end of each stem pulling roller main shaft is in meshed connection with a gearbox, the spiral conveying shafts are arranged at the front end of each stem pulling roller main shaft, and the cutters are evenly fixed to the outer surface of each stem pulling roller main shaft; the cutters are connected end to end to form an annular structure, and the head end of each cutter extends outwards and is provided with an inclined edge. A stem pulling plate is arranged on the outer side of each cutter and is a bent plate composed of a transverse plate and a vertical plate, the transverse plates are fixed to the outer surfaces of the cutters, and the vertical plates are adjacent to the head ends of the cutters. According to the corn stalk cutting device, the cutting device is simplified, a cutter box body does not need to be independently arranged, corn stalks can be directly pulled and cut up through the stalk pulling roller, the structure is simple, and the manufacturing cost is low.

The utility model provides a header of a harvester. The header of the harvester comprises dividers used for distributing crops. The ear picking device is arranged below the dividers and conveys the distributed crops into the header for further treatment; the ear picking device comprises ear picking parts which are arranged side by side; each ear picking part comprises two seedling pulling chain groups; the seedling pulling chain group comprises a first seedling pulling device and a second seedling pulling device which are arranged up and down, and the first seedling pulling device is arranged above the second seedling pulling device through a double-layer chain wheel; the first seedling pulling device comprises a first gear, the first seedling pulling chain is connected with the first gear and the double-layer chain wheel, and the first tensioning device is arranged in the middle of the first seedling pulling device, connected with the first seedling pulling chain and used for adjusting the tightness of the first seedling pulling chain; the first seedling pulling device is arranged on the first mounting seat; the second seedling pulling device comprises a second gear, the second seedling pulling chain is connected with the second gear and the double-layer chain wheel, and the second tensioning device is arranged in the middle of the second seedling pulling device, is in tooth connection with the second seedling pulling chain and is used for adjusting the tightness of the second seedling pulling chain; and the second seedling pulling device is arranged on the second mounting seat.

The invention belongs to the field of agricultural automation equipment, and discloses a double-row leaf mustard harvesting header which comprises a rack, and a transmission device is fixed to the rack; the elastic collecting device is fixed at one end of the rack and comprises a collecting frame and two pairs of tensioning wheel belt sets fixed to the front portion and the rear portion of the collecting frame respectively, and a leaf mustard conveying channel is formed between the two pairs of tensioning wheel belt sets; the clamping and conveying device is arranged in the length direction of the rack and comprises a pair of conveying belts in butt joint with the elastic bundling device. The pair of conveying belts are matched to clamp the leaf mustard conveyed from the leaf mustard conveying channel, and the conveying belts are driven to operate through the transmission device; the adjustable cutting device is installed on the rack and located at the bottom of the clamping and conveying device, and comprises a sliding rail, a hydraulic motor arranged on the sliding rail, a cutting cutterhead fixed to the hydraulic motor, a lead screw lifting machine fixed to the bottom of the sliding rail and a driving motor arranged at the end of the lead screw lifting machine; the two elastic collecting devices and the two clamping and conveying devices are arranged in a matched mode and used for double-row leaf mustard harvesting. The double-row leaf mustard harvesting header is simple in structure, and the cutting position can be flexibly adjusted, so that the applicability is improved.

According to the anti-winding hemp harvester header, the first cutter disc and the rotary header are arranged on the cutting side of the rack, the first cutter disc is provided with the first cutting teeth distributed in the circumferential direction, the second cutter disc parallel to the first cutter disc is arranged on the rotary header, and the second cutter disc is provided with the second cutting teeth arranged in the circumferential direction; the first cutting edges on the first cutting teeth and the second cutting edges on the second cutting teeth are oppositely arranged, and in the using process, the rotary header rotates in the direction of the second cutting edges so as to cut hemp stalks. Due to the fact that the first cutting teeth can support the bast fiber stalks, the cutting quality can be improved in the cutting process, broken stubbles are reduced, and the possibility that bast fiber is wound into the rotating shaft of the rotating header and wound is reduced.

The invention discloses a three-degree-of-freedom adjusting header based on multi-sensor fusion, and the header comprises a cutting execution mechanism which is used for executing a cutting action; the lifting adjusting mechanism is connected with the cutting executing mechanism and used for adjusting the height of the cutting executing mechanism; the inclination angle adjusting mechanism is connected with the lifting adjusting mechanism; the pitching adjusting mechanism is connected with the inclination angle adjusting mechanism; the vehicle body is connected with the pitching adjusting mechanism; the profiling mechanism is connected with the cutting executing mechanism; and the detection and control module is used for establishing an adjustment model by detecting the field environment and controlling the lifting adjustment mechanism, the inclination angle adjustment mechanism, the pitching adjustment mechanism and the profiling mechanism to move through the adjustment model so as to realize attitude adjustment. The problems that an existing header is insufficient in precision, low in response speed and difficult to meet the precise profiling requirement under the complex terrain are solved.

The invention discloses a profiling adjusting device for a header of a corn harvester. Wherein the rear part of the header is rotatably connected with the machine body, and the left and right sides of the bottom surface of the front part of the header are respectively provided with a profiling device; the control system is arranged in a cab; the attitude sensor used for collecting the rotation angle of the gap bridge around the fuselage is mounted on the gap bridge; the header is rotationally connected with the rotating seat; two ends of the hydraulic cylinder III are respectively hinged with the rotating seat and the header; the hydraulic cylinder I and the hydraulic cylinder II are arranged in parallel; two ends of the hydraulic cylinder I and the hydraulic cylinder II are respectively hinged with the rotating seat and the machine body; and the cutting knife is fixed below the middle front part of the header. The risk that the header touches the ground and is damaged can be well reduced, the operation difficulty is reduced, and the automatic corn harvesting degree is improved. The device is used for detecting the height of the header from the ground, is simple in structure, is convenient to install, is higher in anti-interference capability, and can well adapt to a complex working environment.

A harvester header height keeping structure comprises a header serving as a harvesting part of a harvester, a height adjusting device used for adjusting the height of the header above the ground, a control module used for driving the height adjusting device to adjust the height of the header above the ground in real time according to feedback information, and a horizontal measuring device used for monitoring the inclination degree of the harvester relative to the ground. The angle sensor is used for monitoring the inclination degree of the header relative to the harvester, and the control structure is used for inputting and modifying the preset header height. The height of the header is intelligently and automatically adjusted, so that the harvesting efficiency is improved, and the crop loss is reduced.

The invention relates to the technical field of agricultural machinery, and discloses an ear picking plate adjusting system, an ear picker and an ear picking plate adjusting method. When the ear picking plate adjusting system is applied to the ear picking machine for harvesting operation, butt-clamping type contact detection can be conducted on the stem diameter of crops to be harvested entering the harvesting space through the stem diameter detection module, the detection precision is higher, the control module determines the size of the stem diameter according to detection data, and the harvesting efficiency is improved. Therefore, the driving module is controlled to adjust the distance between the two ear picking plates, the width of the harvesting space is adjusted, and it is ensured that the width of the harvesting space can be matched with the stem diameter of crops to be harvested. According to the ear picking plate adjusting system, the size of the harvesting space between the two ear picking plates in the execution module can be automatically adjusted, manual adjustment is not needed, the labor intensity of workers is reduced, it is ensured that the damage rate of fruits is reduced in the harvesting process, and the ear picking efficiency is improved.

The utility model discloses a vertical header clamping conveying chain tensioning device and a corn harvester, and relates to the technical field of agricultural machinery, the vertical header clamping conveying chain tensioning device comprises a tensioning seat and a tensioning support which are located at the two ends of a conveying chain, the tensioning seat is fixedly connected with a driving chain wheel of the conveying chain, and the tensioning support is fixedly connected with a driven chain wheel; a pull rod capable of axially moving is connected between the tensioning seat and the tensioning support, a tensioning pressure spring is sleeved outside the pull rod, one end of the tensioning pressure spring is fixedly connected with the tensioning seat, and the other end of the tensioning pressure spring acts on the tensioning support; the tensioning pressure spring is arranged between the tensioning seat and the tensioning support to be matched with the pull rod, and the tensioning support can be driven by elastic force of the tensioning pressure spring when the conveying chain is loosened, so that a driven chain wheel of the conveying chain is adjusted in a self-adaptive mode, the conveying chain is in a tensioning state, conveying failure is avoided, and the service life of the conveying chain is prolonged. And the stability of the header of the harvester in operation is effectively improved.

A control for the endless set of a rotating harvester head includes a train of transmission stages that encircle on one side behind the gathering channel, rises upward to pass in a horizontal-transverse direction towards the medium above the tray in which the header-conveyors of the head are found, to finally be vertically lowered by a drop-down box that takes the axis of the augers. In turn, the drop box includes two reducing stages to oil-bath gears that concentrate much of the speed reduction coming from the power take-off at the inlet and, likewise, has a construction that reduces the interference in the passage of the harvest of the tray to the gathering channel. Patters located in the innermost turn of the auger on each side of the drop box can drive the crop to change 90° towards the gathering channel, further reducing interference when the flow rate is important.

A hydraulic flail knife corn header comprises a header rack, two gap bridge shafts are symmetrically arranged at the two ends of the rear side of the header rack, and a plurality of ear picking units and a feeding auger are installed on the header rack side by side. The outer ends of the two gap bridge shafts are in transmission connection with input shafts of the ear picking units respectively, and the input shaft of the ear picking unit located at one end is in transmission connection with one end of the feeding auger. The device is characterized in that a hydraulic motor is mounted in the middle of a right ear picking support of each ear picking unit, and lower flail knives are mounted at the lower ends of the hydraulic motors respectively; a transfer case is mounted in the middle of each gap bridge shaft, a hydraulic pump is in transmission connection with each gap bridge shaft through the corresponding transfer case, the hydraulic pumps are variable load-sensitive pumps and are connected with the corresponding hydraulic motors through load-sensitive valves, and feedback oil ports of the load-sensitive valves are communicated with control ports of the hydraulic pumps. The header can meet the high-speed rotation of the lower flail knife, is compact in structure, reduces the cost, can save the installation space, and facilitates the reasonable layout of a narrow space.

The invention relates to a silage harvester header and a using method, and belongs to the technical field of silage harvesting equipment. According to the technical scheme, a grain dividing fork (5) is arranged at the front end of a front feeding roller (2), cutting boards of the front feeding roller (2) and a rear feeding roller (3) are arranged in a crossed and staggered mode, and a split type comb plate (6) is arranged between the front feeding roller and the rear feeding roller; the split type comb plate comprises a front comb plate and a rear comb plate which are detachably connected, the fit clearance between the front comb plate and the rear comb plate can be adjusted, and the working distance between the front comb plate and the rear feeding roller can be changed by adjusting the fit clearance between the front comb plate and the rear comb plate. Therefore, the conveying requirement for cutting of different types of materials is met. The cutting table has the beneficial effects that the split comb plate is adopted, so that material blockage during working of the cutting table is reduced, the comb plate is convenient to replace and maintain, and the working efficiency during harvesting is improved; the feeding device has the characteristics of high feeding efficiency, uniform feeding, efficient and stable conveying and the like.

The utility model discloses a header shield of a corn harvester, which relates to the technical field of corn harvesters and comprises a shield body, an observation window is arranged on the side wall of the shield body, an observation plate is fixedly mounted on the inner side wall of the shield body, a mounting seat is arranged on the side portion of the observation plate, a scraper is movably mounted on the mounting seat, and the scraper is movably mounted on the mounting seat. A groove is formed in the outer side wall of the protective cover body, a shifting table used for controlling the scraper to move is movably installed in the groove, two sets of guide plates are fixedly installed on the outer side wall of the protective cover body, and a protective cover is movably installed between the two sets of guide plates. According to the design scheme, through the design that the observation plate is fixedly installed on the inner side wall of the shield body, the installation base is arranged on the side portion of the observation plate, the scraper is installed on the installation base in a sliding mode, a user pulls the shifting table in the groove, oil dirt attached to the inner side of the observation plate is scraped through the scraper, and then oil dirt on the inner side of the observation plate is removed. Therefore, the observation plate can be cleaned under the condition that the shield body is not detached.